chr6-98917666-C-A

Variant names:

• chr6-98917666-C-A
• rs769532824
• NM_001278716.2:c.566G>T

Variant summary

Our verdict is Uncertain significance. The variant received 4 ACMG points: 4P and 0B. PM2 PP2 PP3

The NM_001278716.2(FBXL4):​c.566G>T​(p.Arg189Leu) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000186 in 1,612,942 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. R189C) has been classified as Uncertain significance.

• Frequency:
  • Genomes: 𝑓 0.0000066 (0 hom., cov: 32)
  • Exomes 𝑓: 0.0000014 (0 hom.)
• Consequence: FBXL4 NM_001278716.2 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 7.54
• Publications: 0 publications found

Genes affected

FBXL4 (HGNC:13601): (F-box and leucine rich repeat protein 4) This gene encodes a member of the F-box protein family, which are characterized by an approximately 40 amino acid motif, the F-box. F-box proteins constitute one subunit of modular E3 ubiquitin ligase complexes, called SCF complexes, which function in phosphorylation-dependent ubiquitination. The F-box domain mediates protein-protein interactions and binds directly to S-phase kinase-associated protein 1. In addition to an F-box domain, the encoded protein contains at least 9 tandem leucine-rich repeats. The ubiquitin ligase complex containing the encoded protein may function in cell-cycle control by regulating levels of lysine-specific demethylase 4A. Alternative splicing results in multiple transcript variants. [provided by RefSeq, Jul 2013]

FBXL4 Gene-Disease associations (from GenCC):

• Leigh syndrome

  Inheritance: AR Classification: DEFINITIVE Submitted by: ClinGen
• mitochondrial DNA depletion syndrome 13

  Inheritance: AR Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: G2P, Labcorp Genetics (formerly Invitae), Genomics England PanelApp, Orphanet

ACMG classification

Our verdict: Uncertain_significance. The variant received 4 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP2: Missense variant in the gene, where a lot of missense mutations are associated with disease in ClinVar. The gene has 24 curated pathogenic missense variants (we use a threshold of 10). The gene has 1 curated benign missense variants. Gene score misZ: 0.55467 (below the threshold of 3.09). Trascript score misZ: 1.2845 (below the threshold of 3.09). GenCC associations: The gene is linked to Leigh syndrome, mitochondrial DNA depletion syndrome 13.
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.793

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_001278716.2. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	FBXL4	NM_001278716.2	MANE Select	c.566G>T	p.Arg189Leu	missense	Exon 5 of 10	NP_001265645.1
	FBXL4	NM_012160.5		c.566G>T	p.Arg189Leu	missense	Exon 4 of 9	NP_036292.2
	FBXL4	NR_103836.2		n.843+8811G>T		intron	N/A

Ensembl Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	FBXL4	ENST00000369244.7	TSL:1 MANE Select	c.566G>T	p.Arg189Leu	missense	Exon 5 of 10	ENSP00000358247.1
	FBXL4	ENST00000229971.2	TSL:1	c.566G>T	p.Arg189Leu	missense	Exon 4 of 9	ENSP00000229971.1

Frequencies

GnomAD3 genomes AF: 0.00000657 AC: 1 AN: 152092 Hom.: 0 Cov.: 32

Gnomad AFR AF: 0.0000241

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.00

Gnomad ASJ AF: 0.00

Gnomad EAS AF: 0.00

Gnomad SAS AF: 0.00

Gnomad FIN AF: 0.00

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.00

Gnomad OTH AF: 0.00

GnomAD2 exomes AF: 0.00000402 AC: 1 AN: 248710 AF XY: 0.00

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00000895

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.00000137 AC: 2 AN: 1460850 Hom.: 0 Cov.: 31 AF XY: 0.00 AC XY: 0 AN XY: 726686

⚠️ The allele balance in gnomAD version 4 Exomes is significantly skewed from the expected value of 0.5.

African (AFR) AF: 0.00 AC: 0 AN: 33450

American (AMR) AF: 0.00 AC: 0 AN: 44672

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26026

East Asian (EAS) AF: 0.00 AC: 0 AN: 39686

South Asian (SAS) AF: 0.00 AC: 0 AN: 86072

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53360

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5762

European-Non Finnish (NFE) AF: 0.00000180 AC: 2 AN: 1111478

Other (OTH) AF: 0.00 AC: 0 AN: 60344

⚠️ The allele balance in gnomAD4 Exomes is highly skewed from 0.5 (p-value = 0.00233887), which strongly suggests a high chance of mosaicism in these individuals.

GnomAD4 genome AF: 0.00000657 AC: 1 AN: 152092 Hom.: 0 Cov.: 32 AF XY: 0.00 AC XY: 0 AN XY: 74276

African (AFR) AF: 0.0000241 AC: 1 AN: 41440

American (AMR) AF: 0.00 AC: 0 AN: 15240

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 3470

East Asian (EAS) AF: 0.00 AC: 0 AN: 5200

South Asian (SAS) AF: 0.00 AC: 0 AN: 4828

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 10592

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 316

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 68006

Other (OTH) AF: 0.00 AC: 0 AN: 2088

Alfa AF: 0.00 Hom.: 0

ExAC AF: 0.00000824 AC: 1

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Mitochondrial DNA depletion syndrome 13 Uncertain:1

Aug 10, 2017

Wong Mito Lab, Molecular and Human Genetics, Baylor College of Medicine

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: reference population

The NM_012160.4:c.566G>T (NP_036292.2:p.Arg189Leu) [GRCH38: NC_000006.12:g.98917666C>A] variant in FBXL4 gene is interpretated to be a Uncertain Significance - Conflicting Evidence based on ACMG guidelines (PMID: 25741868). This variant meets one or more of the following evidence codes reported in the ACMG-guideline. PM2:This variant is absent in key population databases. BP4:Computational evidence/predictors indicate no impact on the FBXL4 structure, function, or protein-protein interaction. Based on this evidence code ClinGen Pathogenicity Calculator (PMID:28081714) suggested that the variant is Uncertain Significance - Conflicting Evidence.

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.72
BayesDel_addAF	Uncertain	0.10	D
BayesDel_noAF	Benign	-0.090
CADD	Pathogenic	27
DANN	Uncertain	1.0
DEOGEN2	Uncertain	0.53	D
Eigen	Uncertain	0.31
Eigen_PC	Uncertain	0.39
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Uncertain	0.92	D
M_CAP	Uncertain	0.089	D
MetaRNN	Pathogenic	0.79	D
MetaSVM	Benign	-0.97	T
MutationAssessor	Uncertain	2.9	M
PhyloP100		7.5
PrimateAI	Uncertain	0.55	T
PROVEAN	Pathogenic	-5.2	D
REVEL	Uncertain	0.37
Sift	Pathogenic	0.0	D
Sift4G	Uncertain	0.0080	D
Polyphen		0.32	B
Vest4		0.90
MutPred		0.49		Loss of MoRF binding (P = 0.0033)
MVP		0.42
MPC		0.43
ClinPred		1.0	D
GERP RS		4.8
Varity_R		0.79
gMVP		0.89
Mutation Taster		=62/38	polymorphism

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.0		Details are displayed if max score is > 0.2

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Other links and lift over

dbSNP: rs769532824; hg19: chr6-99365542;